People swimming in the sea during the heatwave are being warned that Lion's Mane jellyfish are bigger than usual this year.
This type of jellyfish is the most venomous in Irish waters with sightings in the Celtic and Atlantic seas recently.
According to the Irish Times, several swimmers in the west have received hospital treatment for Lion's Mane stings - with symptoms including severe headache, pain, vomiting and even cardiac arrest.
